Explain why the roles and responsibilities of the vice president may change from administration to administration.

Because the vice president has very few official roles, essentially two: presiding over the senate, and casting tier-breaking votes in case of a tie, and becoming the sucessor of the president in case the president dies, renounces, is impeached, etc.

The rest of the roles are more informal ones, and these can be assigned freely by each president. This why the roles and responsabilities of the vice president may change from administration to administration.

answer; the edward snowden leaks of nsa classified material;